1. Technical Field
The present invention relates to an optical connector plug to make an optical connection between optical fibers.
2. Description of the Related Art
An optical fiber used in optical communication performs an optical connection using an optical connector. The optical connector is comprised of an optical connector plug in which an end of the optical fiber is held, and an optical connector adapter to perform, an optical connection between the optical fibers while the optical connector plugs are fixed. As such an optical connector, there is a SC type optical connector (IEC 61754-4) to perform optical connection using a capillary (ferrule cylindrical member) whose outer diameter is approximately 2.5 mm for holding the optical fiber, or a LC type optical connector (IEC 61754-20) to perform optical connection using a capillary (ferrule cylindrical member) whose outer diameter is approximately 1.25 mm for holding an optical fiber or the like.
In FIG. 2 and FIG. 5 of the U.S. Pat. No. 6,293,710 (hereinafter referred to as patent document 1), an optical connector plug in which a ferrule holding an optical fiber inside thereof is inserted in a plug frame, a spring (coil spring) is provided between the ferrule and a stop ring, and the plug frame and the stop ring are engaged and fixed so as to assemble is disclosed. In the optical connector plug disclosed in the patent document 1, a flange of the ferrule and the spring are accommodated in a first accommodation space of the plug frame, and the capillary of the ferrule is accommodated in a second accommodation space of the plug frame.
When a single-mode optical fiber is used, after the core eccentricity direction of the optical fiber is checked and it is determined that the orientation thereof is the position around the axis of the ferrule, the assembly of the optical connector plug is performed while confirming the position around the axis of the ferrule with respect to the plug frame. Further, when an angle polishing processing of the end face of the ferrule (such as an angled PC polishing) is performed, the assembly of the optical connector plug is performed in a state in which the position around the axis of the ferrate is aligned with respect to the plug frame.
In paragraphs “0048”, “0050”, “0069”, “0072” and “0080” and FIGS. 11, 13 and 18 of the United States Patent Application Publication No. US2012/0243832 (hereinafter referred to as patent document 2), an optical connector plug in which a ferrule including a flange of asymmetrical shape with respect to the vertical direction is included and a ferrule accommodation space to accommodate the ferrule of the optical connector plug has a shape corresponding to the flange is disclosed. Further, a method in which when such an optical connector plug is assembled, a dust cap attached with a string is covered on the ferrule, the dust cap attached with the string is passed through the plug frame so that the ferrule is inserted into the plug frame is disclosed.